private void CalculateMetrics(TreeItemCollection items, ref DrawContext context)
{
foreach (var item in items)
{
var props = new TreeItemProperties();
props.item = item;
props.bounds = new RectangleF(0,
context.offset * context.lineHeight,
Width, context.lineHeight);
props.selectBounds = new RectangleF(10 + context.indent * context.indentWidth,
(context.offset + 0.5f) * context.lineHeight - 8,
16, 16);
props.textBounds = new RectangleF(context.indent * context.indentWidth + 30,
context.offset++ *context.lineHeight, Width, context.lineHeight);
properties[item] = props;
if (item.Expanded && item.Children.Count > 0)
{
context.indent++;
CalculateMetrics(item.Children, ref context);
context.indent--;
}
}
}
private void DrawItems(TreeItemCollection items, ref DrawContext context)
{
foreach (var item in items)
{
if (hover?.item == item)
{
context.brush.Color = Color.ToRawColor4();
context.canvas.NativeDeviceContext.FillRectangle(hover.bounds, context.brush);
context.brush.Color = (checkHover ? Backcolor : Forecolor).ToRawColor4();
}
if (item.Children.Count > 0)
{
var select = new RectangleF(context.indent * context.indentWidth + 10,
(context.offset + 0.5f) * context.lineHeight - 8,
16, 16);
context.canvas.NativeDeviceContext.FillRectangle(select, context.brush);
}
context.brush.Color = Forecolor.ToRawColor4();
if (item.Text != null)
{
var rect = new RectangleF(context.indent * context.indentWidth + 30,
context.offset++ *context.lineHeight, Width, context.lineHeight);
context.canvas.NativeDeviceContext.DrawText(item.Text, context.format, rect, context.brush);
}
if (item.Expanded && item.Children.Count > 0)
{
context.indent++;
DrawItems(item.Children, ref context);
context.indent--;
}
}
}
public Tree()
{
Items = new TreeItemCollection(this);
scroller = new Scroller(this);
}
